Study On Flow Field Characteristics Of Elliptical Oil Film Bearing

As rotary machinery is developing towards the direction of large scale, high speed and high capacity, more faults appear in bearing system. At the same time the fault diagnosis become more difficult and maintenance cost is increasing. As the important support part of rotary machinery, the working condition of oil-film bearing directly affects the reliability, life, working accuracy and other technical indexs. The flow field characteristics of oil-film bearing determine system damping and the ability of rotary machinery which can produce enough load-carrying capacity to balance external load. It is the key to the safe and stable operation of the machine. So it is very important to study the flow field characteristics.With the advantages of simply manufacturing, stable operation and well heat dissipation performances, Elliptic oil-film bearing is widely used in various kinds of rotary machinery. This paper is based on elliptical oil-film bearing of one enterprise, theoretical program calculation, fluid field simulation and experimental research were used to study the flow field characteristics. The main contents of this study are as follows.(1) The elliptic oil-film bearing mathematical model was established, and solved through programming. The main content is:Reynolds equation was deduced according to N-S equation and continuity equation, and the model calculation parameters were obtained through contrast. The calculation formula of load-carrying capacity and calculation convergence condition were gained according to the structure characteristics of elliptic oil-film bearing. Then the result was obtained through programming calculation.(2) The physical model of elliptic oil-film bearing was reasonably simplified, and the oil film with and without the consideration of cavitation effect was simulated with FLUENT software. Comparison shows that result with consideration of cavitation effect is more reasonable. Flow field characteristics were analyzed under different journal speed and inlet oil pressure with the consideration of cavitation effect. Because of lower inlet oil pressure, the positive pressure area was failed to form in this model. Therefor the model of double inlet was established and which was simulated under different loadcases.(3) An experimental research on flow field characteristics of elliptic oil-film bearing was completed through self-developed large-scale oil-film bearing test rig. The comparison of theoretical program calculation, fluid field simulation and experimental research shows good agreement among them.